Dike flow and heat transfer with geomembrane defects: experiment and simulation

The damage of geomembranes in dikes can result in leakage. In order to investigate the efficacy of heat tracing in the detection of geomembrane defects, a series of laboratory experiments were conducted utilising a self-made 2D sand trough and temperature sensors. The heat tracing response of geomembrane defects was evaluated. The findings indicate that the temperature distribution within the dike, resulting from geomembrane defects, exhibits a comparable spatial-temporal pattern to that of the seepage field. Furthermore, the heat tracing response is discernible. A flow-heat coupling model (FHCM) was constructed based on the heat transfer theory of porous media and the saturated-unsaturated seepage theory. The accuracy of the FHCM was tested by combining the laboratory experiment results. The The numerical simulation results show that the superposition of multiple geomembrane defects results in an acceleration of leakage. In order to reduce the amount of debugging work required for model parameters, the Morris method was employed to analyse the global sensitivity of six parameters within the FHCM. It was determined that the parameter exhibiting the greatest sensitivity is hydraulic conductivity. This work provides a reference for the wide application of heat tracing technique.